Re: Help diagnosing problem.

I forgot to add that when powered up with just the cpu/IO I get no beeps. Could this be cause by the video board? or should I guess its the I/O or the main board that all the cards plug in to. also there are some corroded pars near where the batteries were but it seemed as if I could get continuity though all of them, possibly the board cant.

PATRICK On May 2, 2008, at 12:35 PM, Ray Arachelian wrote:

>
> Patnukem wrote:
>> I will try a disk in there when I get home and see if it tries to
>> read
>> there is a red light in the disk drive that lights up when the
>> computer is on, it does not click at all. the display in the lisa
>> does not do anything, just the external one, I will try to post a
>> video of it to show. I have two memory cards and two cpu cards so I
>> am fairly sure they are not the problems, Like I said before the I/O
>> card could be it also the main board (the one that holds all the
>> other
>> boards) could also be damaged, it looked kinda bad before I cleaned
>> it. I have put several new caps in the power supply and the computer
>> seems to be getting at least some power, I can tell the front and
>> back switches are working since the computer will turn off when the
>> front or the back is removed.
>>
>
> The Lisa had a very different video display system than most
> monitors of
> the time. While the external video connector is an RCA jack, this is
> not something that can drive most monitors out there. There were a
> few
> that would work, however, but odds are, unless you have a display that
> you know will work with a Lisa, it won't work.
>
> For example, taking the output from that RCA jack and connecting it
> to a
> modern TV, or a composite monitor (such as those that drove, say a
> Commodore 64, or an Apple II) will not work.
>
> I'm a bit weary of the clipped capacitors you've mentioned earlier,
> however; those sound like very bad news to me. You'll probably have
> to
> resolder those. As far as I know, only 2 resistors were cut from the
> I/O board to convert it from a Lisa 1 to a Lisa 2 - no other boards in
> any Lisa should have any cut components.
>
> Can you take a high-res picture of whichever board had the cut
> capacitors, we can compare it to ours and see if we can see what's
> wrong. I think LisaList will accept attachments - at least last
> time I
> checked it did. If not you can email me the photo directly.
>
> When you actually press the power switch to turn it on, do you hear
> any
> sounds at all? any chirping, or clicking? (Those indicate power
> supply
> issues, which can usually be solved by capacitor replacement.)
>
> Once powered up, do you hear any beeps? Usually the Lisa will beep 3x
> when there are issues. The beeps themselves (long/short, low tone or
> high tone) have meaning and can help diagnose what is wrong. But only
> if the CPU board and enough of the I/O board work.
>
> Once powered up, if you push the power switch, does the Lisa power
> off?
> If not, the CPU board might not work either.
>
> Meanwhile I'd urge you to go read the various repair parts of
> http://lisafaq.sunder.net as they may give you clues, and also to copy
> the Lisa schematics to see which components were cut. You can get
> those
> most of what you'd need from lisa.sunder.net/books.html
>
> >

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